Fiber



Patented Apr. 16, 1940 FIBER Earle 0. Whittier and Stephen P. Gould,Washington, D. 0., dedicated to the free use of the l People of theUnited States of America No Drawing. Application M... 19, 1938,

Serial No. 208,830

2 Claims. (01. 28-1) I (Granted under the act of March 3, .1883, asamended April 30, 1928; 870 0. G. 757) This application .is made underthe act of r h 1883, as amended by the act of April 30, 1928, and theinvention herein described and claimed, if patented, may be manufacturedand 6 used by or for the Government of the United States forgovernmental purposes without the payment to us of any royalty thereon.

This application is a continuation in part of the one filed by us onAugust 12, 1937, bearing 10 Serial No. 158,822.

We hereby dedicate the invention herein described to the free use of thePeople of the United States of America to take effect on the granting ofa patent to us.

Our invention deals with fibers made from casein.

The objects of our invention are to produce dispersions of casein (mixedusually with plasticizers and salts), which can be extruded into fibershaving the requisite characteristics of strength, water resistance,flexibility, and softness necessary to make them suitable for use intextiles, and are valuable as substitutes for W001 and other fibers. I

In forming dispersions suitable for extrusions, the casein is dissolvedor dispersed in a solution of some protein solvent. Plasticizers, saltsfor increasing the strength and water-resistance may be incorporated inthe dispersion.

Some of the best plasticizers were found to be the fat acids, 1. e.,those usually obtained by the hydrolysis of oils and fats, or theirsalts. These give to the fibers a highly desirable flexibility,softness, and water repellency. Used alone with the casein dispersion,some loss in strength of the filaments occurs; but by the addition ofsodium aluminate, or other salts, the strength may be considerablyincreased. These filaments are very much better than when unplasticizedcasein is used as such fibers are too brittle, and not so waterresistant. In addition to the fat acids,

other plastlcizersor softeners may be used, as for example, amyllactate, ethylene glycol monobutyl ether, latex (this also increases thewaterproofness); maleic acid, and tartaric acid, or

their salts, or compounds consisting of combinations of organic acidradicals; withmetals or with alkyl or aryl groups.

Calcium chloride, magnesium chloride, or other a salts 'of these metals,can be used (although not in the presence of some plasticizers) ashardening and water-repelling agents in the casein fibers, instead ofsodium aluminate. Ammonlacal or amine solutions of casein work best whenusing calcium and magnesium salts, as complexes 5 are formed which givea more homogeneous solution, and calcium caseinate will not separate soreadily before the dispersion is extruded.

The following-is given to illustrate a preferred procedure for producingfibers comprising casein. l0. Proportions are given in parts.

Example 1 ,Casein 24.0 Water 208.0 1 Sodium hydroxide solution (2N) 8.0Sodium aluminate 1.9 Maleic acid 0.63

The casein was soaked .in part of'the water for 15 to 30 minutes and thesodium hydroxide solu- 1) tion then added. The sodium'aluminate and themaleic acid were dissolved in small portions of the water and added tothecasein solution. This solution was warmed to C. and forced through aspinnerette, of a type commonly used inthe $5 rayon industry, into aprecipitating bath, heated to the same temperature. The composition ofthe precipitating bathwas, expressed in parts: sulfuric acid, 2;formaldehyde, 5; glucose, 10; water, .83. This procedure gives fibershaving the characteristics necessary for use in making yarns andfabrics.

It is understood that our invention is not limited to the above example,as the constituents and proportions, both in the solution comprising 86casein and in the precipitating bath, may be varied over a wide range.The temperatures of the solutions are not limited to 50 C., but may beof any value between room temperature and 2. As an article ofmanufacture, a flber com- 46 prising casein, salts of casein, anddibasic aliphatic acids containinga maximum of 4 carbon atoms.

EARLE O. WHI'I'I'IER. STEPHEN P. GOULD. o

